Juntando Modelação 3D Manual e Procedimental

Na área da modelação tridimensional existem duas grandes vertentes: modelação manual e modelação procedimental. Na primeira, o utilizador modela o objeto interagindo diretamente com o resultado através de ferramentas virtuais que, em alguns casos, se aproximam daquelas utilizadas por modeladores em objetos reais; desta forma permitindo um controlo direto e fino sobre o que está a ser produzido. Em modelação procedimental, os objetos são construídos de forma automática a partir de várias condições definidas pelo utilizador, através de regras textuais numa linguagem dedicada ou de grafos de fluxo de dados, permitindo um produção rápida em em grandes quantidades de conteúdo 3D.No entanto, nem sempre a interação com estes métodos é a mais intuitiva. Em situações em que é necessário introduzir detalhes particulares, o processo de criação procedimental torna-se demasiado trabalhoso. Para esses casos, a modelação manual seria a mais adequada para efetuar correções ou ajustes em detalhes.É assim importante encontrar um meio que permita combinar as vantagens da modelação manual com as vantagens da modelação procedimental, para que os potenciais utilizadores possam criar modelos tridimensionais com maior eficiência. Esta dissertação têm como objetivo avaliar possíveis abordagens de integração das duas vertentes de modelação e o impacto da respetiva utilização. Para tal, foi implementada e testada uma solução que visa integrar a ferramenta de modelação procedimental Construct na ferramenta de modelação manual Blender.The domain of tridimensional modelling contains two major approaches: manual modelling and procedural modeling.In the first, the user models the object interacting directly with the result through virtual tools which, in some cases, work similarly to those utilized by modelers in real objects; thus allowing for direct and rigorous control over what is being produced. In procedural modelling, the objects are created automatically through several user-defined conditions, by textual rules in a dedicated language or data-flow graphs, allowing for quick and large-scale production of 3D content.On the other hand, interaction with these methods isn't always the most intuitive. In cases where it's necessary to introduce particular details, the procedural generation process becomes too taxing. For those situations, manual modelling would be the most adequate to perform corrections or small adjustments over details.So, it is important to find a medium which permits combining the advantages of manual modelling with those of procedural modelling, so that potential users may create tridimensional models with greater efficiency.This dissertation has as its objective the evaluation of possible integrations of the two main approaches of 3D modelling and the impact of the corresponding usage. To that purpose, a solution that aims to integrate the procedural modelling tool Construct in the manual modelling tool Blender was implemented and tested

Simulation des plantes à fleurs

Plants have always intrigued scientists as besides of its sheer importance for the earth, their beauty and enormous variety of shapes tempt to thoroughly inquire about its nature. One of the aspects of this inquiry is the creation of the virtual model in order to mimic real plants to a high degree of accuracy. The focus of our study is the flowering plants, which play a huge role in our life from nutritive and medical purposes to beautifying the environment. Obtaining an accurate geometrical model of a flower is quite useful as it plays an important role in the validation of the virtual model. Besides, the visualization of parameters not traceable directly in living flowering plants is a stand-by in studying their physiology. A huge biological diversity both within and between individuals provides a vast area of objectives which the image synthesis must challenge.Flower modelling constitutes a part of a larger research area, plant modelling. Flowering plants have their particular structural features which are different from the structure of trees, bushes or grass. Still not a lot of emphasis has been placed to date on this problem, as it was categorized within the modelling of plants in general. We chose a procedural modeling using L-systems as a base of our research. L-system is a very powerful method of plant simulation. It provides a means of characterizing the topology of a plant at every stage of its growth. Grasping the plant structure with just several lines of grammar attracted immediate interest and later on evolved into several powerful geometrical interpretation system used in plant modelling. Our purpose is to study efficient ways of describing the structure of flowering plants by means of L-systems. First, we will propose to represent the shapes of leafs, petals, stamens, carpels, etc. with an extension of L-systems – a model based on three dimensional generalized maps – 3Gmaps L-systems, which can be successfully applied for the modelling of flowering plants. The grammar description of the structure of the flowering plants provides an unlimited number of its geometrical interpretations. Second, we will improve the process of grammar writing by adding a new functionality of interactive parameter adjustment. Third, we will propose a new method of inverse modelling of flowering plants, where the user can interactively define the flower characteristics. The algorithm uses this information as an input, which is then analyzed and coded as L-systems grammar. Finally, we will present a method for creating virtual glades of flowers using Kinect gestures. We want to remark that our work has been done with 3Gmaps L-system software platform developed in the scope of the thesis to integrate all the proposed techniques.Les plantes ont longtemps intrigué les scientifiques, qui, avec son importance vitale pour la planète, sa beauté et l'énorme quantité de formes ayant, les rend un sujet attrayant pour la recherche. Un aspect intéressant est la création d'un modèle virtuel capable de simuler de vraies plantes avec un degré élevé de précision. L'objectif de notre étude est les plantes à fleurs, qui jouent un rôle énorme dans notre vie de fins nutritives et médicales à l'embellissement de l'environnement . L'obtention d'un modèle géométrique exacte d'une fleur est très utile, car elle joue un rôle important dans la validation du modèle virtuel. Par ailleurs, la visualisation de paramètres non directement traçables dans les plantes à fleurs vivantes est d'une grande aide à l'étude de la physiologie. L'énorme biodiversité entre les différentes parties d'un spécimen et entre les différents spécimens fournit une vaste zone d'objectifs qui la synthèse d'image doit contester. Modéliser des fleurs est un sous-ensemble d'un espace de recherche beaucoup plus vaste que la modélisation de plantes. Les plantes à fleurs ont des caractéristiques structurelles qui les rendent différentes des structures d'arbres, d’arbustes ou de l’herbe. A ce jour, on ne tient pas une grande importance à essayer cette ligne de recherche d'une façon particulière et en général a été classé dans le contexte plus large de la modélisation des plantes. Nous avons choisi d’utiliser le «L-systems» pour la procédure de la modélisation, et comme base pour notre recherche. Il y a différents mécanismes de catégorisation topologie de la plante dans chacune des étapes de sa croissance. Pour construire le plan de la structure d'une plante, avec une courte grammaire, quelques lignes étaient quelque chose qui dès le premier moment a suscité l'intérêt et par la suite évolué en quelques systèmes d'interprétation géométriques pour la modélisation des plantes. Notre objectif est d'étudier les moyens efficaces de décrire la structure des plantes à fleurs en utilisant L-systems. Tout d'abord, nous proposons de représenter les formes des feuilles, pétales, étamines, carpelles, etc. Avec une extension de L-systems - un modèle basé sur trois cartes généralisées dimensions - 3Gmaps L-systèmes, qui peut être appliquée avec succès pour la modélisation des plantes à fleurs. La description de la grammaire de la structure des plantes à fleurs fournit un nombre illimité de ses interprétations géométriques. Deuxièmement, nous allons améliorer le processus d'écriture de la grammaire par l'ajout d'une nouvelle fonctionnalité de paramétrage interactif. Troisièmement, nous allons proposer une nouvelle méthode de modélisation inverse des plantes à fleurs, où l'utilisateur peut définir de manière interactive les caractéristiques des fleurs. L'algorithme utilise cette information comme une entrée, qui est ensuite analysée et codée en tant que L -systèmes grammaire. Enfin, nous allons présenter une méthode pour créer des clairières de fleurs virtuelles à l'aide de gestes Kinect. Nous voulons faire remarquer que notre travail a été fait avec la plateforme de logiciel 3Gmaps L- système développé dans le cadre de la thèse d'intégrer toutes les techniques proposées

An Adjectival Interface for procedural content generation

Includes abstract.Includes bibliographical references.In this thesis, a new interface for the generation of procedural content is proposed, in which the user describes the content that they wish to create by using adjectives. Procedural models are typically controlled by complex parameters and often require expert technical knowledge. Since people communicate with each other using language, an adjectival interface to the creation of procedural content is a natural step towards addressing the needs of non-technical and non-expert users. The key problem addressed is that of establishing a mapping between adjectival descriptors, and the parameters employed by procedural models. We show how this can be represented as a mapping between two multi-dimensional spaces, adjective space and parameter space, and approximate the mapping by applying novel function approximation techniques to points of correspondence between the two spaces. These corresponding point pairs are established through a training phase, in which random procedural content is generated and then described, allowing one to map from parameter space to adjective space. Since we ultimately seek a means of mapping from adjective space to parameter space, particle swarm optimisation is employed to select a point in parameter space that best matches any given point in adjective space. The overall result, is a system in which the user can specify adjectives that are then used to create appropriate procedural content, by mapping the adjectives to a suitable set of procedural parameters and employing the standard procedural technique using those parameters as inputs. In this way, none of the control offered by procedural modelling is sacrificed â although the adjectival interface is simpler, it can at any point be stripped away to reveal the standard procedural model and give users access to the full set of procedural parameters. As such, the adjectival interface can be used for rapid prototyping to create an approximation of the content desired, after which the procedural parameters can be used to fine-tune the result. The adjectival interface also serves as a means of intermediate bridging, affording users a more comfortable interface until they are fully conversant with the technicalities of the underlying procedural parameters. Finally, the adjectival interface is compared and contrasted to an interface that allows for direct specification of the procedural parameters. Through user experiments, it is found that the adjectival interface presented in this thesis is not only easier to use and understand, but also that it produces content which more accurately reflects usersâ intentions

Framework Para a Modelação Procedimental Integrada de Terrenos Completos

Desde o início dos anos 80 que a modelação procedimental tem sido abordada na criação de terrenos. Inicialmente com o objetivo de criar mapas de elevação revelou, mais tarde, ser um tema com bastante potencial para a modelação de outros componentes de um terreno. Com os sucessivos contributos e o aparecimento de novas técnicas, o estudo da modelação procedimental passou também a abordar outras características, como as redes fluviais, redes de estradas, vegetação, e mais recentemente centros urbanos. Com o objetivo de aumentar o realismo dos modelos obtidos, técnicas baseadas em fenómenos físicos foram concebidas. Apesar do potencial comprovado e da utilização de técnicas de modelação procedimental na criação de terrenos em videojogos e simuladores, existem ainda dificuldades na sua aplicação. A existência de diversas soluções, o facto de isoladamente focarem num conjunto limitado de características do terreno e a falta de controlo do processo de criação têm constituído um entrave na criação de frameworks que permitam gerar terrenos completos e utilizáveis. Neste trabalho foi efetuado o estudo das diferentes técnicas de modelação procedimental para cada característica constituinte de um terreno e foi concebida e desenvolvida uma framework de modelação procedimental. A framework desenvolvida permite a integração dessas técnicas de forma a modelar terrenos completos, com ferramentas que facilitam a interação do utilizador e a alteração de parâmetros no processo de criação. Para demonstrar o potencial da solução desenvolvida, técnicas de modelação procedimental foram implementadas e integradas na framework. Os diferentes meios de parametrização foram identificados para cada técnica implementada e os resultados da parametrização foram analisados nos modelos gerados. A solução desenvolvida no âmbito deste projeto permitiu solucionar o problema da integração e da controlabilidade de diferentes camadas que constituem a modelação de um terreno. Foi efetuada a análise de valor que permitiu identificar os benefícios que a solução introduz na adoção de técnicas de modelação procedimental e na investigação e desenvolvimento de novas técnicas.Since the beginning of the 80s, procedural modeling have been applied in the creation of terrains. Being initially used to create height maps, lately, procedural modeling revealed to have great potential modeling other terrain components. With further contributes and the development of new techniques, other terrain characteristics such as water bodies, road networks, vegetation, and recently, urban centers began to be considered for the application of procedural modeling. To further enhance realism, techniques inspired by physics phenomena have been developed. Despite of proven potential in the use of procedural modeling techniques to create terrains for videogames and simulators, there are still some difficulties in its application. The existence of different solutions, the fact that when isolated they focus in a subset of terrain characteristics and the lack of control over the generation process turn out to be a difficulty in the development of frameworks that could generate complete and usable terrains. In this work, existing procedural modeling techniques were studied for each terrain characteristic and a procedural modeling framework was developed. Thisframework integrates different procedural modeling techniques, allowing them to generate a complete terrain, and delivering easy tools that give control over the modeling process. To demonstrate the potential of the developed solution, procedural modeling techniques were implemented and integrated inside the framework. Different methods of parametrization were identified for each implemented technique and parametrization results were analyzed in generated models. The solution developed in this project solved the integration problem and the controllability of different layers that form a complete terrain modeling. A value analysis were made to identify the benefits that the solution brings in the adoption of procedural modeling techniques and in the investigation and development of new techniques

Non-interactive modeling tools and support environment for procedural geometry generation

This research examines procedural modeling in the eld of computer graphics. Procedural modeling automates the generation of objects by representing models as procedures that provide a description of the process required to create the model. The problem we solve with this research is the creation of a procedural modeling environment that consists of a procedural modeling language and a set of non-interactive modeling tools. A goal of this research is to provide comparisons between 3D manual modeling and procedural modeling, which focus on the modeling strategies, tools and model representations used by each modeling paradigm. A procedural modeling language is presented that has the same facilities and features of existing procedural modeling languages. In addition, features such as caching and a pseudorandom number generator is included, demonstrating the advantages of a procedural modeling paradigm. The non-interactive tools created within the procedural modeling framework are selection, extrusion, subdivision, curve shaping and stitching. In order to demonstrate the usefulness of the procedural modeling framework, human and furniture models are created using this procedural modeling environment. Various techniques are presented to generate these objects, and may be used to create a variety of other models. A detailed discussion of each technique is provided. Six experiments are conducted to test the support of the procedural modeling benets provided by this non- interactive modeling environment. The experiments test, namely parameterisation, re-usability, base-shape independence, model complexity, the generation of reproducible random numbers and caching. We prove that a number of distinct models can be generated from a single procedure through the use parameterisation. Modeling procedures and sub-procedures are re-usable and can be applied to different models. Procedures can be base-shape independent. The level of complexity of a model can be increased by repeatedly applying geometry to the model. The pseudo-random number generator is capable of generating reproducible random numbers. The caching facility reduces the time required to generate a model that uses repetitive geometry

Simulated Ecological Environments for Education: A Tripartite Model Framework of HCI Design Parameters for Situational Learning in Virtual Environments

While there are many studies on collaborative or guided scientific inquiry in real, virtual,and simulated environments, there are few that study the interplay between the design ofthe simulation and the user interface. The main research aim was to decompose thesimulation and user interface into the design parameters that influence attention,curiosity, inquiry, and learning of scientific material and acts of creation for children.The research design investigates what tools support independent exploration of a space,enhance deep learning, and motivate scientific or creative inquiry. A major interest is inthe role that ecological context plays in the perception of spatial information.None of the prior work on learning in virtual environments considered a child-centriccomputer interaction framing, independent of pedagogy and focused on the impact ofuser interface parameters, such as image quality and navigational freedom. A majorcontribution of this research is the construction of the Virtual Trillium Trail, as itrepresents one square mile of biologically accurate scientific plot study data. It is avirtual environment based on statistical data visualization, not fantasy. It allowed for ahighly realistic simulation and scientifically true-to-life visualization, as well as for aplanned orthogonal contrast with exceptionally high internal validity in both system andstatistical research design.Of critical importance is evidence in the pilot study, that virtual reality field trips forstudents may be used to prime before and to reinforce after a real field trip. Thisresearch also showed transfer effects on in-situ learning activity, in both directions.Thus, supports the claim that virtual environments may augment educational practices,not replace them, to maximize the overall learning impact. The other large contributionwas in the activity analysis of the real field trip, where the Salamander Effect is observedas an environmental event, which opened a Teachable Moment event for the teacher, andwhich was then translated into a system design feature, a Salient Event in the userinterface. A main part of this research is the importance of such events, as ways tosupport intrinsic learning activity, and leverage episodic memory.The main empirical contribution to the design of educational virtual environments wasproduced by the 2 x 2 ANOVA with the factors of Visual Fidelity and NavigationalFreedom, set to high and low levels, and the evidence of different effects on KnowledgeGained. The tool has an impact on intrinsic learning, which is measured here by a pretestand a post-test on facts and concepts. A two-factor analysis of variance showed asignificant effect of Visual Fidelity on Knowledge Gained, F(1,60) = 10.54, p = 0.0019.High Visual Fidelity condition has a greater impact on Knowledge Gained (M=30.95, SD=14.76), than Low Visual Fidelity condition (M=19.99, SD = 13.39). Photorealistic has astronger impact on learning than cartoon versions. There was significant interactionbetween Visual Fidelity and Navigational Freedom, F(1,60) = 4.85, p = 0.0315, with thelargest impact in the combined conditions of High Visual Fidelity and High NavigationalFreedom on Knowledge Gained (M=37.44, SD = 13.88). Thus, photorealistic, freenavigation virtual environments double learning, when compared to cartoon versions,ceteris paribus.The next major contribution to the design of the user interface in educational virtualenvironments is the design and use of Salient Events as components to augment thevirtual environment and to facilitate intrinsic inquiry into facts and concepts. A two factoranalysis of variance showed a significant effect of Visual Fidelity on Salient Eventcounts, F(1,60) = 4.35, p = 0.00413. High Visual Fidelity condition has a greater impacton Salient Event counts, (Μ = 14.46, SD = 6), than Low Visual Fidelity condition,(Μ =11.31, SD = 6.37). Using High Visual Fidelity with High Navigational Freedom(showing a strong trend of F(1,60) = 3.23, p = 0.0773) to increase Salient Event countsare critical design features for educational virtual environments, especially since SalientEvents are moderately positively correlated with Knowledge Gained (r = 0.455, N = 64, p= 0.000).Emotional, affective, aesthetic, and subjective attitudes were investigated in the post-experience assessment of the main study on system and learning experience. TotalAttitude is strongly positively and significantly correlated with Awe and Wonder (r =0.727, N = 64, p = 0.000). Also important is the strong, positive, and significantcorrelation of Beauty with Awe and Wonder (r = 0.506, N = 64, p = 0.000). And the onlysignificant subjective emotion or attitude variable correlated to Knowledge Gained, wasAwe and Wonder with a slightly positive statistic: (r = 0.273, N = 64, p = 0.000).Future research will investigate the complexity and causality of such interactions betweenthe child's mental model, the virtual environment, and the user interface in the form ofregression equations, partial differential equations, and Markov models